We have previously shown that heat-killed <i>Lactobacillus brevis</i> SBC8803 (hk-SBC8803) induced the secretion of serotonin and elevated intracellular Ca<sup>2+</sup> concentration in serotonin-producing RIN-14B cells, suggesting that hk-SBC8803 could potentially cause the same effect on other gastrointestinal hormones, including hunger hormone ghrelin.